Table 1.
Effect of different serum depletion strategies on the LOD and LLOQ of synthetic peanut allergen peptide SIDs in serum. Serum was depleted using either a ProteoPrep® 20 Plasma Immunodepletion Kit (depleted 1) or a MARS Hu-6 (depleted 2). LOD: 3sy|x/slope; LLOQ: LOD*3. Instrument LOD and LLOQ are expressed as femtomoles of peptide on-column. ND, not determined due to a lack of an adequate calibration curve; FAD, filter-aided digestion; QQQ, triple quadrupole MRM analysis; Q-TOF, quadrupole time-of-flight MRM analysis. The LOD and the LLOQ are expressed in femtomoles on-column. Additional information of the linear regression parameters can be found in ESM Tables S2.1 and S2.2
| Peptide | Sample | MS type | LOD | LLOQ | Peptide | Sample | LOD | LLOQ | |
|---|---|---|---|---|---|---|---|---|---|
| Ara h 1 (P43237)329–342 | Serum | QQQ | ND | ND | Ara h 2 (Q6PSU2)103–115 | Serum | QQQ | ND | ND |
| Depleted (1) | QQQ | ND | ND | Depleted (1) | QQQ | ND | ND | ||
| Depleted (2) | QQQ | 2.81 | 8.43 | Depleted (2) | QQQ | ND | ND | ||
| Depleted (2) and FAD | QQQ | 2.61 | 7.82 | Depleted (2) and FAD | QQQ | ND | ND | ||
| Depleted (2) and FAD | Q-TOF | 1.28 | 3.85 | Depleted (2) and FAD | Q-TOF | 1.26 | 3.78 | ||
| Ara h 1 (P43237)555–575 | Serum | QQQ | ND | ND | Ara h 2 (Q6PSU2)147–155 | Serum | QQQ | 207.90 | ND |
| Depleted (1) | QQQ | 58.71 | 176.12 | Depleted (1) | QQQ | 141.60 | ND | ||
| Depleted (2) | QQQ | 7.57 | 22.72 | Depleted (2) | QQQ | 1.47 | 4.41 | ||
| Depleted (2) and FAD | QQQ | 0.92 | 2.75 | Depleted (2) and FAD | QQQ | 0.79 | 2.38 | ||
| Depleted (2) and FAD | Q-TOF | Not analysed | Not analysed | Depleted (2) and FAD | Q-TOF | 0.60 | 1.79 | ||
| Ara h 3 (Q647H4)25–41 | Serum | QQQ | ND | ND | Ara h 6 (Q647G9)136–144 | Serum | QQQ | ND | ND |
| Depleted (1) | QQQ | 91.10 | 273.31 | Depleted (1) | QQQ | ND | ND | ||
| Depleted (2) | QQQ | 1.65 | 4.95 | Depleted (2) | QQQ | 4.58 | 13.75 | ||
| Depleted (2) and FAD | QQQ | 1.61 | 4.84 | Depleted (2) and FAD | QQQ | 5.68 | 17.03 | ||
| Depleted (2) and FAD | Q-TOF | Not analysed | Not analysed | Depleted (2) and FAD | Q-TOF | Not analysed | Not analysed | ||
| Ara h 3 (Q647H4)372–384 | Serum | QQQ | ND | ND | Ara h 7 (B4X1D4)143–151 | Serum | QQQ | ND | ND |
| Depleted (1) | QQQ | 51.28 | 153.84 | Depleted (1) | QQQ | 113.39 | ND | ||
| Depleted (2) | QQQ | 3.05 | 9.14 | Depleted (2) | QQQ | 4.75 | 14.25 | ||
| Depleted (2) and FAD | QQQ | 0.95 | 2.82 | Depleted (2) and FAD | QQQ | 0.84 | 2.53 | ||
| Depleted (2) and FAD | Q-TOF | 0.53 | 1.60 | Depleted (2) and FAD | Q-TOF | Not analysed | Not analysed |